Low-level liquid wastes from BNFL Sellafield (formerly known as the Windscale and Calder Works) have been discharged into the Irish Sea since operations began in the early 1950s when the project engineer vacancies in Cumbria were created. Although, at first, the major source of these discharges was the processing of nuclear fuel for the production of nuclear weapons, operations since the late 1950s have been dominated by the reprocessing of fuel from commercial nuclear power programs and thus bringing nuclear jobs in Cumbria, the Lake District.
The most significant low-level radioactive wastes from Sellafield arise both in water used to purge the cooling ponds in which spent fuel elements are kept, and from the reprocessing plant whose low-level liquid wastes are collected and neutralised before being discharged into the Irish sea.
In its early days, Sellafield discharged low level radioactive waste into the sea, using a flocculation process to remove radioactivity from liquid effluent before discharge. Metals dissolved in acidic effluents produced a metal hydroxide flocculent precipitate following the addition of ammonium hydroxide. The suspension was then transferred to settling tanks where the precipitate would settle out, and the remaining clarified liquor, or supernate, would be discharged to the sea. Engineering jobs in Cumbria were created as a result and remain today, influencing house prices in Ulverston, Kendal, West Lakes and Workington and Whitehaven.
Enhanced Actinide Removal Plant (EARP)
In December 1987 design engineers started on the design and construction of the new Enhanced Actinide Removal Plant, again creating senior engineering vacancies in Cumbria. The plant was designed and built to the highest engineering, safety and quality standards, as demanded by the UK nuclear industry, and incorporates the latest technology for minimum maintenance and zero access throughout the plant’s anticipated 30 year lifespan. Handover of the plant, described by BNFL as ‘The Cornerstone’ in their £600 million investment programme to clean up discharges to the Irish Sea, took place in April 1992 and created more engineering jobs in the Lake District. In a similar way to the historic process EARP removes actinides using flocculation. In EARP the effectiveness of the process is enhanced by the addition of reagents to remove the remaining soluble radioactive species. Rather than using a settling process EARP uses cross-flow ultrafiltration to separate the radioactive particles from the discharge water. In 2004 EARP was enhanced to further reduce the quantities of Technetium-99 released into the environment.
The Nuclear Industry and therefore nuclear sector jobs in Cumbria has an ongoing commitment to continue reducing its radioactive liquid discharges into the Irish Sea. The technologies involved will ensure the ongoing need for engineering jobs in Cumbria for many years.